In Russia, coxitis is one of the most common extra-axial manifestations of ankylosing spondylitis (AS). However, many issues regarding its early diagnosis remain unresolved. Objective: to compare the clinical manifestations of coxitis with the data from an instrumental examination of CoRSAR cohort (Cohort of Early Axial Spondyloarthritis) patients. Patients and methods. Examinations were made in 175 patients (mean age, 28.2±5.7 years) diagnosed as having axial spondyloarthritis (axSpA) with inflammatory back pain lasting up to 5 years, which occurred at the age of ≤45 years. There was non-radiographic axSpA (nraxSpA) in 69 patients and AS in 106 patients. 87% of patients were HLA-B27-positive. The median disease duration was 23.8 [1–60] months; BASDAI was 3.3±1.94. Regardless of complaints, all the patients underwent hip X-ray and ultrasound studies and 54 more patients had magnetic resonance imaging (MRI). Results and discussion. The clinical signs of coxitis were present in 95 (54%) patients, of them 60% were diagnosed with AS and 40% had nraxSpA. According to the numerical pain rating scale (NPRS), the median hip joint pain was 4 [3; 7]. Limited joint movement was observed in 6 (3.4%) patients. The level of hip joint pain correlated with BASDAI (r=0.53) and ASDAS (r=0.30). The ultrasound signs of coxitis were detected in 42 (24%) patients; of them 26 (62%) had the clinical manifestations of hip joint injury, and such changes were absent in 16 patients. The patients with ultrasound signs of coxitis were noted to have a higher disease activity; peripheral arthritis and enthesitis were more common. According to MRI, coxitis was diagnosed in 39 (72%) of the 54 examinees, while the disease was asymptomatic in 10%. Conclusion. Different diagnostic methods used in patients with early axSpA could reveal coxitis in 33% of cases. The patients with coxitis show higher laboratory disease activity than those without hip joint injury. It is necessary to include MRI and ultrasound in the mandatory examination of patients with axSpA.

Objective : to study bone mineral density (BMD) of the lumbar spine (LS) and femoral neck (FN) in patients with early axial spondyloarthritis (SpA) and to reveal its association with inflammatory disease activity. Subjects and methods . Seventy-three patients aged 18–45 years with inflammatory back pain lasting at least 3 months and not more than 5 years were examined. Axial SpA was diagnosed according to the 2009 ASAS criteria. BASDAI and ASDAS C-reactive protein (CRP) values were used to estimate disease activity; BASFI was employed to evaluate functional status. The examination encompassed determination of HLA-B27, X-ray of the pelvis and LS, magnetic resonance imaging (MRI) of sacroiliac joints, LS, and hip joints (in the presence of clinical signs of their injuries), densitometry of LS (L I-IV ) and FN. By taking into account the young age of patients, the Z-score was applied to measure BMD. The latter is considered lower if the Z-score is 1–2 standard deviations (SD) in at least one of the segments under study. Results . The median Z-score was -0.7 (-1.3; -0.3) SD for FN and 0.9 (-1.6; -0.5) SD for LS. Reduced BMD in at least one of the segments under study was detected in 13 (17.8%) patients: that in LS and FN in 11 (15.1%) and 5 (6.8%) patients, respectively. Lower BMD was observed in two segments in 3 (4.1%) patients. No association was found between lower BMD and age, gender, disease activity (BASDAI, ASDAS), and laboratory inflammatory markers (erythrocyte sedimentation rate (ESR) and CRP). A relationship was established between inflammatory changes according to the data of MRI of LS (MRI spondylitis) and reduced BMD in the same segment. MRI spondylitis was detected in 8 patients. Five and 3 patients with spondylitis of LS were found to have lower and normal BMD in this segment, respectively. Six out of 65 patients without MRI spondylitis in LS had its reduced BMD and the remaining (n=59) patients had its normal BMD (p=0.0014). Conclusion . There was an association between the active inflammatory changes as evidenced by LS MRI and the reduced BMD in this segment of the axial skeleton. Our data validate the hypothesis that in early axial SpA, bone is lost in the vertebral bodies due to local inflammation.

Background The association between MRI inflammation and bone loss in early axial spondyloarthritis (axSpA) patients is not sufficiently studied. Objectives Establishing the association between MRI inflammation of sacroiliac joints (SIJs), lumbar spine (LS) and hip joints (HJs) and bone loss in the nearby bone-joint system in early axial axSpA patients. Methods 73 patients (33 men and 40 women) with early axSpa were examined: mean disease duration 19.9±14.4 months. Patients fulfilled ASAS criteria. Mean age 28.3±6.4 years, mean BASDAI 4.1±1.9; mean ASDAS-CRP 2.7±1.3; mean ESR 21.9±17.6; mean CRP 29.0±38.5; 66 (90.4%) patients were HLA-B27 positive. MRI of SIJs, LS and HJs (in case of hip joint involvement) was performed on Signa Ovation 0.35 T scanner (matrix 288x192). BMD was measured using dual energy x-ray absorptiometry (DXA) of the femoral neck (FN) and lumbar spine (LS) (L2–4). BMD reduction was defined as T score ≤−1. Results MRI inflammation of SIJs and/or LS and/or HJs has been found in 62 (84.9%) patients. Among the 62 patients of this group 44 (71.0%) had BMD reduction in FN and/or LS. And in the group of patients without MRI inflammation (n=11) nobody had bone loss (p=0.0001). MRI sacroiliitis (SI) was observed in 53 (72.6%) patients: 37 (69.8%) of them had BMD reduction in FN and/or LS, and 16 (30.2%) patients of this group had normal BMD values (p=0.007). MRI SI has been found in 32 out of 37 (86.5%) patients that had BMD reduction in the LS; in the group of patients without bone loss in the LS (n=36) MRI SI was observed in 21 (58.3%) patients (p=0.007). MRI SI has been found in 21 out of 27 (77.8%) patients that had BMD reduction in the FN; in the group of patients without bone loss in the FN (n=46) MRI SI was observed in 32 (69.6%) patients (p=0.45). Conclusions Correlation has been detected between inflammatory lesions in SIJs and/or LS and/or HJs and bone loss in FN and/or LS. There is an association between existence of active MRI SI and BMD reduction in the LS. This demonstrates that in patients with early axSpA bone loss is a result of inflammation. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.2435